Computers are commonly employed in the analysis of structures. One widely used computer analysis method is known as finite element analysis. In finite element analysis, the user first generates a computerized drawing of a unitary structure to be analyzed. The computer then divides the drawing of the structure into a plurality of elements. Forces and stresses on each element of the structure are then calculated. If the stresses on the structure are found to exceed the strength of the material from which it is formed, the user must redesign the structure. Although finite element analysis is a useful tool in the design process, the user must perform all the design work.
The present invention is directed to a computer apparatus and method for generating and/or analyzing the stability of a structure where the structure is formed from multiple predefined discrete components fastened together, for example, a bridge, truss, crane, etc. The structure is represented, by a representing member, as a series of bodies fixed in place by stationary joints. The joints have known properties and are listed by a listing member. Each joint is assigned a torque capacity corresponding to the known properties by an assigning member. An analysis member calculates the torque exerted on each joint and compares the calculated torques with respective torque capacities of the joints to determine stability of the structure.
In preferred embodiments, the strength of the joints is lower than the strength of the bodies. In one preferred embodiment, the torque capacity for each joint is provided from a table containing torque capacities for known joint properties. In another preferred embodiment, the torque capacity for each joint is calculated. At least one of the bodies is fixed to the ground with at least one of the stationary joints. Parameters for the structure are entered with a user interface. The parameters define the structure either for analysis or for providing instructions to a generating member for generating a model of the structure. Multiple models of the structure may be generated until at least one of the models is determined to be stable. The calculated exerted torques are compared with the torque capacities along a first plane to analyze two dimensional stability of the structure and along a second plane orthogonal to the first plane to analyze three dimensional stability of the structure. Stability analysis results are provided through an output interface.